[PATCH v2 2/2] bugreport: generate config whitelist based on docs

[Emily Shaffer <emilyshaffer@google.com>]

Add a new step to the build to generate a whitelist of git-config
variables which are appropriate to include in the output of
git-bugreport. New variables can be added to the whitelist by annotating
their documentation in Documentation/config with the line
"// bugreport-include".

Some configs are private in nature, and can contain remote URLs,
passwords, or other sensitive information. In the event that a user
doesn't notice their information while reviewing a bugreport, that user
may leak their credentials to other individuals, mailing lists, or bug
tracking tools inadvertently. Heuristic blacklisting of configuration
keys is imperfect and prone to false negatives; given the nature of the
information which can be leaked, a whitelist is more reliable.

In order to prevent staleness of the whitelist, add a mechanism to
generate the whitelist from annotations in the config documentation,
where contributors are already used to documenting their new config
keys.

Additionally, add annotations to the sendemail config documentation in
order to demonstrate a proof of concept.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
---
 .gitignore                             |  1 +
 Documentation/config/sendemail.txt     | 68 +++++++++++++-------------
 Makefile                               |  9 +++-
 bugreport-generate-config-whitelist.sh |  4 ++
 git-bugreport-config-whitelist         | 22 ---------
 5 files changed, 47 insertions(+), 57 deletions(-)
 create mode 100755 bugreport-generate-config-whitelist.sh
 delete mode 100644 git-bugreport-config-whitelist

diff --git a/.gitignore b/.gitignore
index b4f5433084..65cc74c748 100644
--- a/.gitignore
+++ b/.gitignore
@@ -26,6 +26,7 @@
 /git-blame
 /git-branch
 /git-bugreport
+/git-bugreport-config-whitelist
 /git-bundle
 /git-cat-file
 /git-check-attr
diff --git a/Documentation/config/sendemail.txt b/Documentation/config/sendemail.txt
index 0006faf800..69f3e4f219 100644
--- a/Documentation/config/sendemail.txt
+++ b/Documentation/config/sendemail.txt
@@ -1,63 +1,63 @@
-sendemail.identity::
+sendemail.identity:: // bugreport-exclude
 	A configuration identity. When given, causes values in the
 	'sendemail.<identity>' subsection to take precedence over
 	values in the 'sendemail' section. The default identity is
 	the value of `sendemail.identity`.
 
-sendemail.smtpEncryption::
+sendemail.smtpEncryption:: // bugreport-include
 	See linkgit:git-send-email[1] for description.  Note that this
 	setting is not subject to the 'identity' mechanism.
 
-sendemail.smtpssl (deprecated)::
+sendemail.smtpssl (deprecated):: // bugreport-exclude
 	Deprecated alias for 'sendemail.smtpEncryption = ssl'.
 
-sendemail.smtpsslcertpath::
+sendemail.smtpsslcertpath:: // bugreport-exclude
 	Path to ca-certificates (either a directory or a single file).
 	Set it to an empty string to disable certificate verification.
 
-sendemail.<identity>.*::
+sendemail.<identity>.*:: // bugreport-exclude
 	Identity-specific versions of the 'sendemail.*' parameters
 	found below, taking precedence over those when this
 	identity is selected, through either the command-line or
 	`sendemail.identity`.
 
-sendemail.aliasesFile::
-sendemail.aliasFileType::
-sendemail.annotate::
-sendemail.bcc::
-sendemail.cc::
-sendemail.ccCmd::
-sendemail.chainReplyTo::
-sendemail.confirm::
-sendemail.envelopeSender::
-sendemail.from::
-sendemail.multiEdit::
-sendemail.signedoffbycc::
-sendemail.smtpPass::
-sendemail.suppresscc::
-sendemail.suppressFrom::
-sendemail.to::
-sendemail.tocmd::
-sendemail.smtpDomain::
-sendemail.smtpServer::
-sendemail.smtpServerPort::
-sendemail.smtpServerOption::
-sendemail.smtpUser::
-sendemail.thread::
-sendemail.transferEncoding::
-sendemail.validate::
-sendemail.xmailer::
+sendemail.aliasesFile:: // bugreport-exclude
+sendemail.aliasFileType:: // bugreport-exclude
+sendemail.annotate:: // bugreport-include
+sendemail.bcc:: // bugreport-include
+sendemail.cc:: // bugreport-include
+sendemail.ccCmd:: // bugreport-include
+sendemail.chainReplyTo:: // bugreport-include
+sendemail.confirm:: // bugreport-include
+sendemail.envelopeSender:: // bugreport-include
+sendemail.from:: // bugreport-include
+sendemail.multiEdit:: // bugreport-include
+sendemail.signedoffbycc:: // bugreport-include
+sendemail.smtpPass:: // bugreport-exclude
+sendemail.suppresscc:: // bugreport-include
+sendemail.suppressFrom:: // bugreport-include
+sendemail.to:: // bugreport-include
+sendemail.tocmd:: // bugreport-include
+sendemail.smtpDomain:: // bugreport-include
+sendemail.smtpServer:: // bugreport-include
+sendemail.smtpServerPort:: // bugreport-include
+sendemail.smtpServerOption:: // bugreport-include
+sendemail.smtpUser:: // bugreport-exclude
+sendemail.thread:: // bugreport-include
+sendemail.transferEncoding:: // bugreport-include
+sendemail.validate:: // bugreport-include
+sendemail.xmailer:: // bugreport-include
 	See linkgit:git-send-email[1] for description.
 
-sendemail.signedoffcc (deprecated)::
+sendemail.signedoffcc (deprecated):: // bugreport-exclude
 	Deprecated alias for `sendemail.signedoffbycc`.
 
-sendemail.smtpBatchSize::
+sendemail.smtpBatchSize:: // bugreport-include
 	Number of messages to be sent per connection, after that a relogin
 	will happen.  If the value is 0 or undefined, send all messages in
 	one connection.
 	See also the `--batch-size` option of linkgit:git-send-email[1].
 
-sendemail.smtpReloginDelay::
+sendemail.smtpReloginDelay:: // bugreport-include
 	Seconds wait before reconnecting to smtp server.
 	See also the `--relogin-delay` option of linkgit:git-send-email[1].
diff --git a/Makefile b/Makefile
index 69801a1c45..a62bbefb8f 100644
--- a/Makefile
+++ b/Makefile
@@ -639,6 +639,10 @@ SCRIPT_PYTHON += git-p4.py
 SCRIPT_SH_GEN = $(patsubst %.sh,%,$(SCRIPT_SH))
 SCRIPT_PERL_GEN = $(patsubst %.perl,%,$(SCRIPT_PERL))
 SCRIPT_PYTHON_GEN = $(patsubst %.py,%,$(SCRIPT_PYTHON))
+SCRIPT_DEPENDENCIES = git-bugreport-config-whitelist
+
+$(SCRIPT_DEPENDENCIES): Documentation/config/*.txt
+	sh bugreport-generate-config-whitelist.sh
 
 # Individual rules to allow e.g.
 # "make -C ../.. SCRIPT_PERL=contrib/foo/bar.perl build-perl-script"
@@ -656,17 +660,20 @@ install-perl-script: $(SCRIPT_PERL_GEN)
 install-python-script: $(SCRIPT_PYTHON_GEN)
 	$(INSTALL) $^ '$(DESTDIR_SQ)$(gitexec_instdir_SQ)'
 
-.PHONY: clean-perl-script clean-sh-script clean-python-script
+.PHONY: clean-perl-script clean-sh-script clean-python-script clean-script-dependencies
 clean-sh-script:
 	$(RM) $(SCRIPT_SH_GEN)
 clean-perl-script:
 	$(RM) $(SCRIPT_PERL_GEN)
 clean-python-script:
 	$(RM) $(SCRIPT_PYTHON_GEN)
+clean-script-dependencies:
+	$(RM) $(SCRIPT_DEPENDENCIES)
 
 SCRIPTS = $(SCRIPT_SH_GEN) \
 	  $(SCRIPT_PERL_GEN) \
 	  $(SCRIPT_PYTHON_GEN) \
+	  $(SCRIPT_DEPENDENCIES) \
 	  git-instaweb
 
 ETAGS_TARGET = TAGS
diff --git a/bugreport-generate-config-whitelist.sh b/bugreport-generate-config-whitelist.sh
new file mode 100755
index 0000000000..ca6b232024
--- /dev/null
+++ b/bugreport-generate-config-whitelist.sh
@@ -0,0 +1,4 @@
+#!/bin/sh
+
+grep -RhPo ".*(?=:: \/\/ bugreport-include)" Documentation/config \
+  >git-bugreport-config-whitelist
diff --git a/git-bugreport-config-whitelist b/git-bugreport-config-whitelist
deleted file mode 100644
index e4f07f7175..0000000000
--- a/git-bugreport-config-whitelist
+++ /dev/null
@@ -1,22 +0,0 @@
-http.version
-protocol.version
-protocol.persistent-https.allow
-protocol.rpc.allow
-protocol.sso.allow
-submodule.repolike
-trace2.eventtarget
-trace2.configparams
-color.ui
-core.pager
-sendemail.smtpencryption
-sendemail.smtpserver
-sendemail.smtpserverport
-sendemail.smtpsslcertpath
-credential.helper
-merge.tool
-grep.linenumber
-rerere.enabled
-core.repositoryformatversion
-core.filemode
-core.bare
-core.logallrefupdates
-- 
2.23.0.rc1.153.gdeed80330f-goog